These studies continuing since 1970 have been directed toward the evaluation of accuracy, clinical utility, and cost effectiveness of various computer systems for analysis of routine electrocardiograms (ECG's). BIBLIOGRAPHIC REFERENCES: 1. Bailey, J.J., Horton, M.R., Itscoltz S.B.: The importance of reproducibility testing of computer programs for electrocardiographic interpretation: Application to the automatic vectorcardiographic analysis program (AVA 3.4) Comp. and Biomed. Res. 9:301, August, 1976. 2. Bailey, J.J., Horton, M.R.: Advantages of automation of ECG analysis with conventional (heuristic) criteria. Trends in Computer-processed Electrocardiograms in 98. Edited by J.H. van Bemmel and J.L. Willems. North Holland Publishing Company, New York, 1977, pages 221-228.